Currently I am running Virtualbox 4.3.6 on Crunchbang "Waldorf" (based on Debian Wheezy)

I was able to install a few different guest linux systems but once I reboot, they never boot back up to the desktop. Now I have deleted all of the virtual machines I created and am trying to create a new one and it will not even boot into the installer. I just get a black screen and nothing happens. Any thoughts on why this is?

Do you mean on reboot of the VMs or on reboot of the host system? If the later, do you shut down the VMs before you reboot the host?

No, I mean reboot of the VM. I can install and configure a VM but once I power it down in Virtualbox it seems like I can never start it back up. The next time I start it , it usually hangs before booting into the desktop environment. Now I just tried to boot a fedora live iso and it won't even boot into the desktop to install. I have tried about 5 different distros as VM machines and it doesn't matter which it is which leads me to believe it's an issue with VirtualBox. The version I have is the latest which I downloaded from their site. The one that appears in the repository of my host computer (Crunchbang) is only 4.1. So maybe this newer version doesn't play well for some reason?

Be sure you delete by the virtual machine to include all files associated with any previous vm's.

If you simply create a new vm that has no hard drive and attach a known good iso then it should boot. This assumes enough ram, good host OS, and maybe support in processor and motherboard. You could have some glitch on the bios that disabled vm support. Could be that you simply have to create the proper vm type such as x86 or 64bit. If you use some phrase in naming the vm on creation like fedora 64 it should automatically pick a 64 bit client hardware.

Live cd/dvd type of images won't return from power down too. I assume you know that. One can save the state to return almost any vm client to the saved point. I use that a lot.

I hope this question isn't out of line; I'm seeking clarity.

Do you "power down" the VM by clicking on the X in the window border and telling VirtualBox to "power down" the VM or do you use the menu or terminal in the virtualized OS to issue a shutdown command to the virtualized OS?

I'm asking because I have used VirtualBox extensively on several different host systems (Mageia, Mint, Slackware, Debian, Ubuntu, and Windows, among others) and have not encountered this issue; I have always had the guest distro issue a "shutdown" command to itself. Once it shuts down, I close the VM window, if it does not close on its own. And it has always restarted on command.

The log file is called VBox.log and resides in the VM log file folder. Typically this will be a directory like this:
examine it's contents for clues.

I am talking about the host machine package that gives you usb support and other stuff for clients. If you did remove it than reinstall virtualbox. Installing it breaks the virtualbox kernel module loaders. Having to load the virtualbox kernel modules every reboot is not worth the effort to use thumb drives with clients.

yes...but I'm trying to use a usb guitar interface in the guest OS and I can't do that without the guest additions. But that's good to know! Guess I'll have to install Jack and other audio packages on my host os

Switch to KVM faster and natively supports usb pass through with virt-manager (at least on centos it does)

I really don't know what all the virtualbox hype is about.

You should just have sound. If the sound doesn't come from the client then it is the client's issue.